Bringing a Paginated API

This documentation uses Power BI as an example, but it can be transposed to other BI tools, or other tools that can consume a paginated API.

1. Two Worlds, Two Logics

Concept	What it is	How it acts
Relational Table (Power BI)	A fixed-size grid of rows and columns. You ask for it once and get the whole set.	“All the data is already on the shelf; pick it up in one go.”
Paginated API Endpoint	A web service that delivers data in slices (“pages”) of 10, 50, 100… records at a time. Each page includes a pointer to the next one.	“The data is in a novel—read page 1, then page 2, and so on.”

2. The Integration Strategy

Think of yourself as building a small courier service between the novel (API) and the shelf (Power BI):

1. Initial Request – Get Page 1
   • Send the first GET request (often with page=1 and page_size=n``).
2. Loop – Keep Turning the Pages
   • Inspect the response: it contains both the records and a hint about the next page (nextPageToken, page=2, etc.).
   • Repeat the request with the new page parameters until the API says, “No more pages.”
3. Accumulate – Build a Single Dataset
   • Append each page’s rows into one growing collection (a list, DataFrame, or Power Query table).
   • Once the loop ends, you have a complete, flat table.
4. Load into Power BI
   • Deliver that finished table to Power BI (as a CSV, parquet, database table, or via Power Query’s Web.Contents function wrapped in a loop).

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3. Where the Script Fits

Power BI itself cannot iterate over pages; the script acts as the translator

Paginated API  →  Script (loops, concatenates)  →  Single flat file/table  →  Power BI

• What language? Common choices are Python (with pandas & requests) or Power Query M (using List.Generate for the loop).
• What does it do?
  1. Handles authentication once.
  2. Executes the loop described above.
  3. Writes/returns a consolidated table Power BI can refresh.

Key takeaway: Pagination is only an API-side efficiency mechanism; your script neutralizes it by stitching every page back together before Power BI ever sees the data.

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4. Refreshing Going Forward

• Scheduled refresh in Power BI simply reruns the script.
• The loop safeguards you against future growth—if the task list doubles, the script just turns more pages.

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5. Mental Model & Analogy

API Novel	Script Courier	Power BI Library
Chapters/Pagination	Courier reads all chapters	Final bound book on the shelf

Whenever you refresh, the courier re-reads the novel from chapter 1 to “The End,” prints a fresh copy, and hands it to the library. Power BI patrons never worry about chapters—they always get the full story.

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Summary for the Data Analyst

1. Pagination ≠ Table – The API sends one “chapter” at a time.
2. Use a Looping Script – It turns the pages, collects everything, and hands Power BI a single table.
3. Zero Code Needed to Understand – Just remember: read all pages, append them together, then load.

Once you’re comfortable with that concept, the actual Python/Power Query example you already have will make perfect sense—it’s simply the automation of the page-turning process.